This seems like a simple one, since it's already integrated on some objects; I do a lot of CAD in Anim8or - which, Steve, the software is really becoming great for! - but it'd be useful the Mesh Editor dialogue (or something like that) could show the dimensions of an object.

One other thing.. Anim8or has some nice rounding-features for numbers like in the Grid Settings dialogue, BUT it makes for a hard time doing accurate 1/16 inch (0,0625 in) measurements on an object when Anim8or rounds that value it to 0.06